Two-way anti-drip distributing valve



Aug. 12, 1958 I w. M. Ross TWO-WAY ANTI-*DRIP DISTRIBUTING VALVE Filed Sept. 25, 1955 I I f 1 INVENT OR Mum 07. 055

ATTORNEY Patented Aug. 12, 1958 TWO-WAY ANTI-DRIP DISTRIBUTING VALVE William M. Ross, Memphis, Tenn.

Application September 23, 1955, Serial No. 536,212

8 Claims. (Cl. 137-609) This invention relates to a two-way distributing valve in which fluid from a single inlet is alternately switched to either of two outlets and, more particularly, to a valve which, in closing an outlet, sucks back fluid which otherwise normally would rest in and, perchance, drip from the outlet.

The primary object of the invention is to provide a distributing valve having plungers closable against floating valve seats, the plungers respectively closing in directions away from the outlets controlled thereby. It is herein proposed that each side of the valve have two-phase closing movements, in the first of which phase a plunger closes against a floating seat so as to shut off communication between an inlet and the outlet controlled thereby. In the second closing phase, the plunger and seat move together, as a piston, to increase the volume on the outlet side of the plunger and thereby draw back fluid from the outlet. It is intended also that the opening of each side of the valve be also two phase motions, first to unseat the plunger from its floating seat and, second, to return the then idle floating seat to a position of readiness to meet the plunger on its return or closing stroke.

These and other objects will be apparent from the following specification and drawing, in which;

Fig. 1 is a longitudinal cross-section of the assembly; and,

Fig. 2 is an enlarged transverse section along the line 2-2 of Fig. 1.

Referring now tothe drawing, in which like reference numerals denote similar elements, the distributing valve 2 includes a cylindrical casing 4 enclosing a valve chamber 5 having a central inlet passage 6, and outlet passages 8 and 10 respectively disposed at opposite ends of the chamber. A valve shaft 12 having spaced abutments 14 and 16 straddling its middle, is reciprocated longitudinally in chamber 5 by a lever 18 having a forked free end engaged over valve shaft 12 between abutments 8 and 10 and its opposite end aflixed at 20 to an oscillatable control shaft 21. Control shaft 21 is mounted in bearings 22 in an alcove 23 of easing 4, it being apparent that when control shaft 21 is rocked in one direction or the other, as indicated by the curved double-ended arrow in Fig. l, valve shaft 12 will correspondingly be moved by lever 18 towards one end or the other of chamber 5. In Fig. 1, valve shaft 12 is shown in its extreme position predominantly in the right-hand portion of chamber 5. When control shaft 21 is rocked clockwise as seen in Fig. 1, valve shaft 12 is thereby moved to a corresponding position predominantly in the left-hand end of chamber 5.

Aflixed on opposite ends of valve shaft 12 are a pair of valve plungers 26 and 28 respectively. Since the plungers are identical and the opposite sides of the valve are symmetrical, only plunger 28 and the cooperating elements will be detailed.

Valve plunger 28 is formed with a solid central body 29 and radiating spokes 30 whose outer ends 31 slidably support body 29 centrally in cylindrical casing 4. A floating seat ring 32 slidably sealed by 0 rings 34 against on its outer side. A similar floating seat ring 38 is provided in the opposite side of the valve chamber. Spiders 40 and 42 respectively aflixed on valve shaft 12 are alternately engagable with the inner sides of the floating seat rings for purposes described hereinbelow, and stop rods 44 and 46 are fixed on and extend inwardly from the opopsite end plates 48 and 50, respectively. The stop rods are arranged to extend between thespoke bearings of the valve and to be engaged by the floating seat rings to limit their movements towards their respective ends of the valve chamber. The end plates 48 and 50 are fastened on flanges 52 by bolts 54 and a cap plates 56 in secured by bolts 58 to a flange 60 on alcove 23.

In operation of valve 2, it will be assumed that fluid from inlet 6 is to be alternately distributed through outlet passages 10 and 8. Control shaft 21 is first rocked counter-clockwise soas to shift valve shaft 12 to the right towards the position shown in Fig. l. The initial movement of shaft 12 unseats the solid body 29 from seat 36 of floating seat ring 32, thereby establishing a passage for the fluid from inlet 6 through the central portion of valve chamber 5, through spider 40, centrally through floating seat ring 32, thence past the spokes 30 and around the solid body 29 of valve plunger 28, and out via outlet passage 10. Thefriction inherent in the engagement between the slidable seal and the inner side wall of casing 4 provides sufiicient drag on the seat ring so that, as the solid body 29 of valve plunger 28 starts to move away from the seat ring, a crack is established between the edge of the valve body and the inclined seat 36 of the seat ring. Aswill be apparent from Fig. l, the edge-to-surface contact between the solid body 29 and the inclined surface of seat 36 is such that only a small crack between them is required to permit fluid to flow from the high pressure side, i. e., toward the central portion of valve chamber 5, to the outer side of seatring 32, 7

thereby equalizing the pressures on both sides of the seat ring. If slow moving, highly viscous fluids are distributed, floating seat ring 32 may follow valve plunger 28 until the seat ring engages the ends of stop rods 44, whereupon the seat ring is blocked against further outward movement while the valve plunger moves further outwardly. As valve shaft continues its movement towards the right, spider 40 picks up floating ring 32, which was previously disposed inwardly towards the center of the valve cham ber in a position corresponding oppositely to that of floating seat ring 33, and pushes it outwardly until it engages the inner ,ends of stop rods 44. Meanwhile, as the solid body portion 29 of valve plunger 26 moves inwardly, it engages the seat 36 of floating seat ring 38 and closes the formerly open passage through the left-hand portion of chamber 5 so that plunger 26 and floating seat ring 38 move together, in the manner of a solid piston, to the position illustrated in Fig. l. The solid piston-like move ment of the valve plunger 26 and floating seat ring 38 away from outlet passage 8, after outlet flow therepast has been cut off, increases the volume of the valve chamber inwardly of outlet passage 8 so that fluid therein is sucked back into the valve chamber. Subsequently, when control shaft 21 is rocked clockwise, the valving actions are reversed so that communication from inlet passage 8 is first established, then valve plunger 28 engages floating seat ring 32 to block communication between inlet 6 and outlet 10 and, finally, to suck lead liquid in outlet 10.

Valve 2 is especially, although not exclusively, useful for distributing highly viscous liquids or semi-liquids to dispensing nozzles, not shown, connected to outlet passages 8 and 10, wherein sharp and accurate cut-01f is necessary, and where residual dripping must be prevented as, for instance, when containers are to be neatly filled a to accurate measure. By altering the lengths of stop rods 44 and 46, and repositioning spiders 40 and 42 on valve shaft 12, the amount of suck-back can be altered,

and the incidents of closure may be varied.

The invention isnot limited to the structure detailed herein, but is intended to cover allsubstitutions, modifications and equivalents within the scope of the following claims:

I claim:

l. A valve'having a chamber with outlets adjacent opposite ends thereof andan inlet between said outlets, a pair of seats mounted in said chamber between the inlet and the outlets and respectively associated by proximity with said outlets, a pair of plungers respectively associated with said seats disposed on the outlet sides thereof, means for reciprocating said plungers so as to move one away from the adjacent outlet and towards its associated seat and'to move the other towards the adjacent outlet and away from its associated seat and vice versa, means mounting said. seats for reciprocating movement in said chamber whereby, upon being engaged by their associated plungers, said seats and plungers move together as a piston away from the associated outlets so as to suck back fluid therefrom, lost motion means respectively connecting said plungers and the associated seats for returning the seats towards the associated outlet upon predetermined movement of the plungers towards their associated outlets; said plungers and seats permitting the flow offluid therepast when disengaged, and means for limiting the movement of said seats towards their associated outlets.

2. The combination claimed in claim 1, the means for reciprocating said plungers providing a unitary connection therebetween so that the plungers reciprocate simultaneously in the same directions.

3. The combination claimed in claim 1, and means slidably sealing said seats to the chamber wall.

4. In a valve, an elongate hollow cylinder having an outlet opening at each end thereof and an inlet opening intermediate the ends, a pair of annular seats slidably sealed to the inner wall of the cylinder and respectively associated by proximity with said outlets, a shaft extending axially of the cylinder and having outer ends extending through said annular seats, plungers for said 4 seats, said plungers being disposed on the outer ends of said shaft between their seats and associated outlets, means for reciprocating said shaft axially in said cylinder whereby to engage one of said plungers against its seat and move the latter away from the associated outlet while moving the other plunger in the direction away from its seat and towards the associated outlet, means on said shaft spaced inwardly from the outer ends and disposed inwardly of said seats, said means being engagable with said seats and constituting lost-motion connections between the same and their plungers whereby, after predetermined outward movement of said plungers, said seats are moved outwardly therewith, the plungers and seats, when engaged, constituting pistons for sucking back fluid from the associated outlets and, when disengaged, permitting fluid to flow therepast from said inlet to the associated outlet, and means for limiting the movement of said seats towards their associated outlets.

5. The combination claimed in claim 4, and rings, slidably sealing said seats against the inner wall of the cylinder.

6. The combination claimed in claim 4, the means on said shaft comprising spiders afiixed on said shaft.

7. The combination claimed in claim 4, and circumferentially spaced bearings on said plungers slidably supporting the same in said cylinder. 7

8. The combination claimed in claim 7, the means for limiting the movement of said seats comprising stop members aflixed in the ends of said cylinder, said stop members passing between the circumferentially spaced bearings on the plungers and engaging said seats for limiting the movement thereof towards their associated outlets.

References Cited in the file of this patent UNITED STATES PATENTS 921,890 Rider May 18, 1909 1,177,100 Grandjean Mar. 28, 1916 2,279,010 Nichols Apr. 7, 1942 FOREIGN PATENTS 797,444 France Apr. 27, 1936 

